Enable User Rights

Hello!

I have a problem. I want to mark/highlight/underline some text passages in a datasheet, I use Adobe Reader 9.

Under Tools>Customize Toolbars you can select some Tools to highlight the text, but there is a note on the

bottom of this customize window which says: "Only available when document rights are enabled".

I can't use these tools, so I think this imply that my user rights aren't enabled.

How can I enable them?

Thanks for help!